org.apache.hadoop.hbase

Class MetaTableAccessor

java.lang.Object

org.apache.hadoop.hbase.MetaTableAccessor

@InterfaceAudience.Private
public final class MetaTableAccessor
extends Object

Read/write operations on hbase:meta region as well as assignment information stored to hbase:meta.

Some of the methods of this class take ZooKeeperWatcher as a param. The only reason for this is when this class is used on client-side (e.g. HBaseAdmin), we want to use short-lived connection (opened before each operation, closed right after), while when used on HM or HRS (like in AssignmentManager) we want permanent connection.

HBASE-10070 adds a replicaId to HRI, meaning more than one HRI can be defined for the same table range (table, startKey, endKey). For every range, there will be at least one HRI defined which is called default replica.

Meta layout

For each table there is single row named for the table with a 'table' column family. The column family currently has one column in it, the 'state' column:

 table:state => contains table state
 

For the catalog family, see the comments of CatalogFamilyFormat for more details.

TODO: Add rep_barrier for serial replication explanation. See SerialReplicationChecker.

The actual layout of meta should be encapsulated inside MetaTableAccessor methods, and should not leak out of it (through Result objects, etc)

See Also:

CatalogFamilyFormat, ClientMetaTableAccessor

Method Summary

Modifier and Type	Method and Description
static Put	addDaughtersToPut(Put put, RegionInfo splitA, RegionInfo splitB) Adds split daughters to the Put
static Put	addEmptyLocation(Put p, int replicaId)
static Put	addLocation(Put p, ServerName sn, long openSeqNum, int replicaId)
static Put	addRegionInfo(Put p, RegionInfo hri)
static Put	addRegionStateToPut(Put put, RegionState.State state)
static void	addRegionsToMeta(Connection connection, List<RegionInfo> regionInfos, int regionReplication) Adds a hbase:meta row for each of the specified new regions.
static void	addRegionsToMeta(Connection connection, List<RegionInfo> regionInfos, int regionReplication, long ts) Adds a hbase:meta row for each of the specified new regions.
static void	addSplitsToParent(Connection connection, RegionInfo regionInfo, RegionInfo splitA, RegionInfo splitB) Adds daughter region infos to hbase:meta row for the specified region.
static void	deleteTableState(Connection connection, TableName table) Remove state for table from meta
static void	fullScanMetaAndPrint(Connection connection)
static List<Result>	fullScanRegions(Connection connection) Performs a full scan of hbase:meta for regions.
static void	fullScanRegions(Connection connection, ClientMetaTableAccessor.Visitor visitor) Performs a full scan of hbase:meta for regions.
static void	fullScanTables(Connection connection, ClientMetaTableAccessor.Visitor visitor) Performs a full scan of hbase:meta for tables.
static List<RegionInfo>	getAllRegions(Connection connection, boolean excludeOfflinedSplitParents) Lists all of the regions currently in META.
static Result	getCatalogFamilyRow(Connection connection, RegionInfo ri)
static PairOfSameType<RegionInfo>	getDaughterRegions(Result data) Returns the daughter regions by reading the corresponding columns of the catalog table Result.
static Table	getMetaHTable(Connection connection) Callers should call close on the returned Table instance.
static Pair<RegionInfo,ServerName>	getRegion(Connection connection, byte[] regionName) Deprecated. use getRegionLocation(Connection, byte[]) instead
static HRegionLocation	getRegionLocation(Connection connection, byte[] regionName) Returns the HRegionLocation from meta for the given region
static HRegionLocation	getRegionLocation(Connection connection, RegionInfo regionInfo) Returns the HRegionLocation from meta for the given region
static Result	getRegionResult(Connection connection, byte[] regionName) Gets the result in hbase:meta for the specified region.
static Scan	getScanForTableName(org.apache.hadoop.conf.Configuration conf, TableName tableName) This method creates a Scan object that will only scan catalog rows that belong to the specified table.
static List<RegionInfo>	getTableRegions(Connection connection, TableName tableName) Gets all of the regions of the specified table.
static List<RegionInfo>	getTableRegions(Connection connection, TableName tableName, boolean excludeOfflinedSplitParents) Gets all of the regions of the specified table.
static List<Pair<RegionInfo,ServerName>>	getTableRegionsAndLocations(Connection connection, TableName tableName) Do not use this method to get meta table regions, use methods in MetaTableLocator instead.
static List<Pair<RegionInfo,ServerName>>	getTableRegionsAndLocations(Connection connection, TableName tableName, boolean excludeOfflinedSplitParents) Do not use this method to get meta table regions, use methods in MetaTableLocator instead.
static TableState	getTableState(Connection conn, TableName tableName) Fetch table state for given table from META table
static Map<TableName,TableState>	getTableStates(Connection conn) Fetch table states from META table
static ServerName	getTargetServerName(Result r, int replicaId) Returns the ServerName from catalog table Result where the region is transitioning on.
static Delete	makeDeleteFromRegionInfo(RegionInfo regionInfo, long ts) Generates and returns a Delete containing the region info for the catalog table
static Put	makePutFromRegionInfo(RegionInfo regionInfo, long ts) Generates and returns a Put containing the region into for the catalog table
static Put	makePutFromTableState(TableState state, long ts) Construct PUT for given state
static void	putsToMetaTable(Connection connection, List<Put> ps) Put the passed ps to the hbase:meta table.
static Result	scanByRegionEncodedName(Connection connection, String regionEncodedName) Scans META table for a row whose key contains the specified regionEncodedName, returning a single related Result instance if any row is found, null otherwise.
static void	scanMeta(Connection connection, byte[] startRow, byte[] stopRow, ClientMetaTableAccessor.QueryType type, ClientMetaTableAccessor.Visitor visitor)
static void	scanMeta(Connection connection, byte[] startRow, byte[] stopRow, ClientMetaTableAccessor.QueryType type, Filter filter, int maxRows, ClientMetaTableAccessor.Visitor visitor)
static void	scanMeta(Connection connection, byte[] startRow, byte[] stopRow, ClientMetaTableAccessor.QueryType type, int maxRows, ClientMetaTableAccessor.Visitor visitor) Performs a scan of META table.
static void	scanMeta(Connection connection, ClientMetaTableAccessor.Visitor visitor, TableName tableName, byte[] row, int rowLimit) Performs a scan of META table for given table starting from given row.
static void	scanMetaForTableRegions(Connection connection, ClientMetaTableAccessor.Visitor visitor, TableName tableName)
static void	updateRegionLocation(Connection connection, RegionInfo regionInfo, ServerName sn, long openSeqNum, long masterSystemTime) Updates the location of the specified region in hbase:meta to be the specified server hostname and startcode.
static void	updateRegionState(Connection connection, RegionInfo ri, RegionState.State state) Update state column in hbase:meta.
static void	updateTableState(Connection conn, TableName tableName, TableState.State actual) Updates state in META Do not use.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

fullScanRegions

public static void fullScanRegions(Connection connection,
                                   ClientMetaTableAccessor.Visitor visitor)
                            throws IOException

Performs a full scan of hbase:meta for regions.

Parameters:

connection - connection we're using

visitor - Visitor invoked against each row in regions family.

Throws:

IOException

fullScanRegions

public static List<Result> fullScanRegions(Connection connection)
                                    throws IOException

Performs a full scan of hbase:meta for regions.

Parameters:

connection - connection we're using

Throws:

IOException

fullScanTables

public static void fullScanTables(Connection connection,
                                  ClientMetaTableAccessor.Visitor visitor)
                           throws IOException

Performs a full scan of hbase:meta for tables.

Parameters:

connection - connection we're using

visitor - Visitor invoked against each row in tables family.

Throws:

IOException

getMetaHTable

public static Table getMetaHTable(Connection connection)
                           throws IOException

Callers should call close on the returned Table instance.

Parameters:

connection - connection we're using to access Meta

Returns:

An Table for hbase:meta

Throws:

NullPointerException - if connection is null

IOException

getRegion

@Deprecated
public static Pair<RegionInfo,ServerName> getRegion(Connection connection,
                                                                byte[] regionName)
                                                         throws IOException

Deprecated. use getRegionLocation(Connection, byte[]) instead

Gets the region info and assignment for the specified region.

Parameters:

connection - connection we're using

regionName - Region to lookup.

Returns:

Location and RegionInfo for regionName

Throws:

IOException

getRegionLocation

public static HRegionLocation getRegionLocation(Connection connection,
                                                byte[] regionName)
                                         throws IOException

Returns the HRegionLocation from meta for the given region

Parameters:

connection - connection we're using

regionName - region we're looking for

Returns:

HRegionLocation for the given region

Throws:

IOException

getRegionLocation

public static HRegionLocation getRegionLocation(Connection connection,
                                                RegionInfo regionInfo)
                                         throws IOException

Returns the HRegionLocation from meta for the given region

Parameters:

connection - connection we're using

regionInfo - region information

Returns:

HRegionLocation for the given region

Throws:

IOException

getCatalogFamilyRow

public static Result getCatalogFamilyRow(Connection connection,
                                         RegionInfo ri)
                                  throws IOException

Returns:

Return the HConstants.CATALOG_FAMILY row from hbase:meta.

Throws:

IOException

getRegionResult

public static Result getRegionResult(Connection connection,
                                     byte[] regionName)
                              throws IOException

Gets the result in hbase:meta for the specified region.

Parameters:

connection - connection we're using

regionName - region we're looking for

Returns:

result of the specified region

Throws:

IOException

scanByRegionEncodedName

public static Result scanByRegionEncodedName(Connection connection,
                                             String regionEncodedName)
                                      throws IOException

Scans META table for a row whose key contains the specified regionEncodedName, returning a single related Result instance if any row is found, null otherwise.

Parameters:

connection - the connection to query META table.

regionEncodedName - the region encoded name to look for at META.

Returns:

Result instance with the row related info in META, null otherwise.

Throws:

IOException - if any errors occur while querying META.

getAllRegions

public static List<RegionInfo> getAllRegions(Connection connection,
                                             boolean excludeOfflinedSplitParents)
                                      throws IOException

Lists all of the regions currently in META.

Parameters:

connection - to connect with

excludeOfflinedSplitParents - False if we are to include offlined/splitparents regions, true and we'll leave out offlined regions from returned list

Returns:

List of all user-space regions.

Throws:

IOException

getTableRegions

public static List<RegionInfo> getTableRegions(Connection connection,
                                               TableName tableName)
                                        throws IOException

Gets all of the regions of the specified table. Do not use this method to get meta table regions, use methods in MetaTableLocator instead.

Parameters:

connection - connection we're using

tableName - table we're looking for

Returns:

Ordered list of RegionInfo.

Throws:

IOException

getTableRegions

public static List<RegionInfo> getTableRegions(Connection connection,
                                               TableName tableName,
                                               boolean excludeOfflinedSplitParents)
                                        throws IOException

Gets all of the regions of the specified table. Do not use this method to get meta table regions, use methods in MetaTableLocator instead.

Parameters:

connection - connection we're using

tableName - table we're looking for

excludeOfflinedSplitParents - If true, do not include offlined split parents in the return.

Returns:

Ordered list of RegionInfo.

Throws:

IOException

getScanForTableName

public static Scan getScanForTableName(org.apache.hadoop.conf.Configuration conf,
                                       TableName tableName)

This method creates a Scan object that will only scan catalog rows that belong to the specified table. It doesn't specify any columns. This is a better alternative to just using a start row and scan until it hits a new table since that requires parsing the HRI to get the table name.

Parameters:

tableName - bytes of table's name

Returns:

configured Scan object

getTableRegionsAndLocations

public static List<Pair<RegionInfo,ServerName>> getTableRegionsAndLocations(Connection connection,
                                                                            TableName tableName)
                                                                     throws IOException

Do not use this method to get meta table regions, use methods in MetaTableLocator instead.

Parameters:

connection - connection we're using

tableName - table we're looking for

Returns:

Return list of regioninfos and server.

Throws:

IOException

getTableRegionsAndLocations

public static List<Pair<RegionInfo,ServerName>> getTableRegionsAndLocations(Connection connection,
                                                                            @Nullable
                                                                            TableName tableName,
                                                                            boolean excludeOfflinedSplitParents)
                                                                     throws IOException

Do not use this method to get meta table regions, use methods in MetaTableLocator instead.

Parameters:

connection - connection we're using

tableName - table to work with, can be null for getting all regions

excludeOfflinedSplitParents - don't return split parents

Returns:

Return list of regioninfos and server addresses.

Throws:

IOException

fullScanMetaAndPrint

public static void fullScanMetaAndPrint(Connection connection)
                                 throws IOException

Throws:

IOException

scanMetaForTableRegions

public static void scanMetaForTableRegions(Connection connection,
                                           ClientMetaTableAccessor.Visitor visitor,
                                           TableName tableName)
                                    throws IOException

Throws:

IOException

scanMeta

public static void scanMeta(Connection connection,
                            @Nullable
                            byte[] startRow,
                            @Nullable
                            byte[] stopRow,
                            ClientMetaTableAccessor.QueryType type,
                            ClientMetaTableAccessor.Visitor visitor)
                     throws IOException

Throws:

IOException

scanMeta

public static void scanMeta(Connection connection,
                            ClientMetaTableAccessor.Visitor visitor,
                            TableName tableName,
                            byte[] row,
                            int rowLimit)
                     throws IOException

Performs a scan of META table for given table starting from given row.

Parameters:

connection - connection we're using

visitor - visitor to call

tableName - table withing we scan

row - start scan from this row

rowLimit - max number of rows to return

Throws:

IOException

scanMeta

public static void scanMeta(Connection connection,
                            @Nullable
                            byte[] startRow,
                            @Nullable
                            byte[] stopRow,
                            ClientMetaTableAccessor.QueryType type,
                            int maxRows,
                            ClientMetaTableAccessor.Visitor visitor)
                     throws IOException

Performs a scan of META table.

Parameters:

connection - connection we're using

startRow - Where to start the scan. Pass null if want to begin scan at first row.

stopRow - Where to stop the scan. Pass null if want to scan all rows from the start one

type - scanned part of meta

maxRows - maximum rows to return

visitor - Visitor invoked against each row.

Throws:

IOException

scanMeta

public static void scanMeta(Connection connection,
                            @Nullable
                            byte[] startRow,
                            @Nullable
                            byte[] stopRow,
                            ClientMetaTableAccessor.QueryType type,
                            @Nullable
                            Filter filter,
                            int maxRows,
                            ClientMetaTableAccessor.Visitor visitor)
                     throws IOException

Throws:

IOException

getTargetServerName

@Nullable
public static ServerName getTargetServerName(Result r,
                                                       int replicaId)

Returns the ServerName from catalog table Result where the region is transitioning on. It should be the same as CatalogFamilyFormat.getServerName(Result,int) if the server is at OPEN state.

Parameters:

r - Result to pull the transitioning server name from

Returns:

A ServerName instance or CatalogFamilyFormat.getServerName(Result,int) if necessary fields not found or empty.

getDaughterRegions

public static PairOfSameType<RegionInfo> getDaughterRegions(Result data)

Returns the daughter regions by reading the corresponding columns of the catalog table Result.

Parameters:

data - a Result object from the catalog table scan

Returns:

pair of RegionInfo or PairOfSameType(null, null) if region is not a split parent

getTableState

@Nullable
public static TableState getTableState(Connection conn,
                                                 TableName tableName)
                                          throws IOException

Fetch table state for given table from META table

Parameters:

conn - connection to use

tableName - table to fetch state for

Throws:

IOException

getTableStates

public static Map<TableName,TableState> getTableStates(Connection conn)
                                                throws IOException

Fetch table states from META table

Parameters:

conn - connection to use

Returns:

map {tableName -> state}

Throws:

IOException

updateTableState

public static void updateTableState(Connection conn,
                                    TableName tableName,
                                    TableState.State actual)
                             throws IOException

Updates state in META Do not use. For internal use only.

Parameters:

conn - connection to use

tableName - table to look for

Throws:

IOException

makePutFromRegionInfo

public static Put makePutFromRegionInfo(RegionInfo regionInfo,
                                        long ts)
                                 throws IOException

Generates and returns a Put containing the region into for the catalog table

Throws:

IOException

makeDeleteFromRegionInfo

public static Delete makeDeleteFromRegionInfo(RegionInfo regionInfo,
                                              long ts)

Generates and returns a Delete containing the region info for the catalog table

addDaughtersToPut

public static Put addDaughtersToPut(Put put,
                                    RegionInfo splitA,
                                    RegionInfo splitB)
                             throws IOException

Adds split daughters to the Put

Throws:

IOException

putsToMetaTable

public static void putsToMetaTable(Connection connection,
                                   List<Put> ps)
                            throws IOException

Put the passed ps to the hbase:meta table.

Parameters:

connection - connection we're using

ps - Put to add to hbase:meta

Throws:

IOException

addRegionStateToPut

public static Put addRegionStateToPut(Put put,
                                      RegionState.State state)
                               throws IOException

Throws:

IOException

updateRegionState

public static void updateRegionState(Connection connection,
                                     RegionInfo ri,
                                     RegionState.State state)
                              throws IOException

Update state column in hbase:meta.

Throws:

IOException

addSplitsToParent

public static void addSplitsToParent(Connection connection,
                                     RegionInfo regionInfo,
                                     RegionInfo splitA,
                                     RegionInfo splitB)
                              throws IOException

Adds daughter region infos to hbase:meta row for the specified region.

Note that this does not add its daughter's as different rows, but adds information about the daughters in the same row as the parent. Now only used in snapshot. Use RegionStateStore if you want to split a region.

Parameters:

connection - connection we're using

regionInfo - RegionInfo of parent region

splitA - first split daughter of the parent regionInfo

splitB - second split daughter of the parent regionInfo

Throws:

IOException - if problem connecting or updating meta

addRegionsToMeta

public static void addRegionsToMeta(Connection connection,
                                    List<RegionInfo> regionInfos,
                                    int regionReplication)
                             throws IOException

Adds a hbase:meta row for each of the specified new regions. Initial state for new regions is CLOSED.

Parameters:

connection - connection we're using

regionInfos - region information list

Throws:

IOException - if problem connecting or updating meta

addRegionsToMeta

public static void addRegionsToMeta(Connection connection,
                                    List<RegionInfo> regionInfos,
                                    int regionReplication,
                                    long ts)
                             throws IOException

Adds a hbase:meta row for each of the specified new regions. Initial state for new regions is CLOSED.

Parameters:

connection - connection we're using

regionInfos - region information list

ts - desired timestamp

Throws:

IOException - if problem connecting or updating meta

makePutFromTableState

public static Put makePutFromTableState(TableState state,
                                        long ts)

Construct PUT for given state

Parameters:

state - new state

deleteTableState

public static void deleteTableState(Connection connection,
                                    TableName table)
                             throws IOException

Remove state for table from meta

Parameters:

connection - to use for deletion

table - to delete state for

Throws:

IOException

updateRegionLocation

public static void updateRegionLocation(Connection connection,
                                        RegionInfo regionInfo,
                                        ServerName sn,
                                        long openSeqNum,
                                        long masterSystemTime)
                                 throws IOException

Updates the location of the specified region in hbase:meta to be the specified server hostname and startcode.

Uses passed catalog tracker to get a connection to the server hosting hbase:meta and makes edits to that region.

Parameters:

connection - connection we're using

regionInfo - region to update location of

openSeqNum - the latest sequence number obtained when the region was open

sn - Server name

masterSystemTime - wall clock time from master if passed in the open region RPC

Throws:

IOException

addRegionInfo

public static Put addRegionInfo(Put p,
                                RegionInfo hri)
                         throws IOException

Throws:

IOException

addLocation

public static Put addLocation(Put p,
                              ServerName sn,
                              long openSeqNum,
                              int replicaId)
                       throws IOException

Throws:

IOException

addEmptyLocation

public static Put addEmptyLocation(Put p,
                                   int replicaId)
                            throws IOException

Throws:

IOException